Method for behaviour recognition based on line-of-sight estimation, electronic equipment, and storage medium

ABSTRACT

A method and device for behavior recognition based on line-of-sight estimation are provided. The method is as follows. An image is collected. It is detected whether the image includes a face. When the image includes a face, it is determined whether the face in the image is a face with closed eyes. When the face in the image is not with closed eyes, a line-of-sight direction angle of a target to which the face belongs, and a distance between the face and an image collecting unit, are computed. It is determined whether the target has a set behavior based on the line-of-sight direction angle and the distance.

CROSS-REFERENCE TO RELATED APPLICATION

This application is based on and claims priority to Chinese Application No. 202011310316.2 filed on Nov. 20, 2020, the content of which is hereby incorporated by reference in its entirety for all purposes.

TECHNICAL FIELD

The present disclosure relates to interaction control technology based on a smart instruction, and more particularly, to a method and device for behavior recognition based on line-of-sight estimation, electronic equipment, and a storage medium.

BACKGROUND

Smart interaction is a mode of interaction between a human and smart electronic equipment where an operating instruction is generated based on user behavior detection. A user behavior includes a multi-modal behavior such as recognizing a face, a voice, an expression, a gesture, etc. A user behavior is detected, sensed, and interpreted to generate an operating instruction, so as to control providing a precise matching response by equipment, improving interaction experience comprehensively. Currently, in face recognition, accuracy in expression or behavior recognition fails to meet a corresponding requirement.

SUMMARY

The present disclosure provides a method for behavior recognition based on line-of-sight estimation, electronic equipment, and a storage medium.

According to a first aspect of the present disclosure, a method for behavior recognition is provided, including: collecting an image, by an image collecting unit; detecting whether the image comprises a face; in response to the image comprising a face, determining whether the face in the image is a face with closed eyes, wherein the face in the image is a face of a target; in response to determining that the face in the image is not with closed eyes, computing a line-of-sight direction angle of the target, and a distance between the face and the image collecting unit; and determining whether the target has a set behavior based on the line-of-sight direction angle and the distance.

According to a second aspect of the present disclosure, an electronic equipment is provided, including a processor and a memory for storing processor executable instructions. The processor is configured, by calling the executable instructions in the memory, to implement: collecting an image, by an image collecting unit; detecting whether the image comprises a face; in response to the image comprising a face, determining whether the face in the image is a face with closed eyes, wherein the face in the image is a face of a target; in response to determining that the face in the image is not with closed eyes, computing a line-of-sight direction angle of the target, and a distance between the face and the image collecting unit; and determining whether the target has a set behavior based on the line-of-sight direction angle and the distance.

According to a third aspect of the present disclosure, a non-transitory computer-readable storage medium is provided, the storage medium having stored therein instructions which, when executed by a processor of electronic equipment, allow the electronic equipment to implement: collecting an image, by an image collecting unit; detecting whether the image comprises a face; in response to the image comprising a face, determining whether the face in the image is a face with closed eyes, wherein the face in the image is a face of a target; in response to determining that the face in the image is not with closed eyes, computing a line-of-sight direction angle of the target, and a distance between the face and the image collecting unit; and determining whether the target has a set behavior based on the line-of-sight direction angle and the distance.

It should be understood that the general description above and the detailed description below are illustrative and explanatory only, and do not limit the present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate examples consistent with the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

FIG. 1 is a flowchart of a method for behavior recognition based on line-of-sight estimation according to one or more examples of the present disclosure.

FIG. 2 is a schematic diagram of a structure of a device for behavior recognition based on line-of-sight estimation according to one or more examples of the present disclosure.

FIG. 3 is a block diagram of an electronic equipment according to one or more examples of the present disclosure.

DETAILED DESCRIPTION

Reference will now be made in detail to illustrative embodiments, examples of which are illustrated in the accompanying drawings. The following description refers to the accompanying drawings in which the same numbers in different drawings represent the same or similar elements unless otherwise represented. The implementations set forth in the following description of illustrative embodiments do not represent all implementations consistent with the present disclosure. Instead, they are merely examples of devices and methods consistent with aspects related to the present disclosure as recited in the appended claims. The illustrative implementation modes may take on multiple forms, and should not be taken as being limited to examples illustrated herein. Instead, by providing such implementation modes, embodiments herein may become more comprehensive and complete, and comprehensive concept of the illustrative implementation modes may be delivered to those skilled in the art. Implementations set forth in the following illustrative embodiments do not represent all implementations in accordance with the subject disclosure. Rather, they are merely examples of the apparatus and method in accordance with certain aspects herein as recited in the accompanying claims.

Reference throughout this specification to “one embodiment,” “an embodiment,” “an example,” “some embodiments,” “some examples,” or similar language means that a particular feature, structure, or characteristic described is included in at least one embodiment or example. Features, structures, elements, or characteristics described in connection with one or some embodiments are also applicable to other embodiments, unless expressly specified otherwise.

Note that although a term such as first, second, third may be adopted in an example herein to describe various kinds of information, such information should not be limited to such a term. Such a term is merely for distinguishing information of the same type. For example, without departing from the scope of the examples herein, the first information may also be referred to as the second information. Similarly, the second information may also be referred to as the first information. Depending on the context, a “if” as used herein may be interpreted as “when” or “while” or “in response to determining that”.

In addition, described characteristics, structures or features may be combined in one or more implementation modes in any proper manner. In the following descriptions, many details are provided to allow a full understanding of examples herein. However, those skilled in the art will know that the technical solutions of examples herein may be carried out without one or more of the details; alternatively, another method, component, device, option, etc., may be adopted. Under other conditions, no detail of a known structure, method, device, implementation, material or operation may be shown or described to avoid obscuring aspects of examples herein.

The terms “module,” “sub-module,” “circuit,” “sub-circuit,” “circuitry,” “sub-circuitry,” “unit,” or “sub-unit” may include memory (shared, dedicated, or group) that stores code or instructions that can be executed by one or more processors. A module may include one or more circuits with or without stored code or instructions. The module or circuit may include one or more components that are directly or indirectly connected. These components may or may not be physically attached to, or located adjacent to, one another.

A block diagram shown in the accompanying drawings may be a functional entity which may not necessarily correspond to a physically or logically independent entity. Such a functional entity may be implemented in form of software, in one or more hardware modules or integrated circuits, or in different networks and/or processor devices and/or microcontroller devices.

A terminal may sometimes be referred to as a smart terminal. The terminal may be a mobile terminal. The terminal may also be referred to as User Equipment (UE), a Mobile Station (MS), etc. A terminal may be equipment or a chip provided therein that provides a user with a voice and/or data connection, such as handheld equipment, onboard equipment, etc., with a wireless connection function. Examples of a terminal may include a mobile phone, a tablet computer, a notebook computer, a palm computer, a Mobile Internet Device (MID), wearable equipment, Virtual Reality (VR) equipment, Augmented Reality (AR) equipment, a wireless terminal in industrial control, a wireless terminal in unmanned drive, a wireless terminal in remote surgery, a wireless terminal in a smart grid, a wireless terminal in transportation safety, a wireless terminal in smart city, a wireless terminal in smart home, etc.

FIG. 1 is a flowchart of a method for behavior recognition based on line-of-sight estimation according to an example of the present disclosure. As shown in FIG. 1, a method for behavior recognition based on line-of-sight estimation according to an example of the present disclosure includes steps as follows.

In S11, an image is collected. It is detected whether the image includes a face.

Examples of the present disclosure are applicable to a scene in which electronic equipment such as a smart speaker, a voice robot, etc., is smartly operated. Of course, the target to be operated may be electronic equipment such as a mobile phone, a notebook, a tablet computer, a game machine, etc. After a user behavior recognition application of examples of the present disclosure has been installed in the electronic equipment, an operating instruction may be generated corresponding to recognition of a user behavior, to operate the electronic equipment.

In examples of the present disclosure, an image is collected through a camera, etc., installed on electronic equipment, to collect a face image of an operator, to analyze the face image to determine a set behavior of the user, and generate an operating instruction corresponding to the set behavior of the user, so that the operator can control the electronic equipment without manually operating the electronic equipment.

In examples of the present disclosure, the camera of the electronic equipment captures an image in real time, or captures an image after detecting a corresponding event, such as activating an image collecting mode after detecting an ambient sound exceeding a set decibel. A collection interval for capturing images may be set as needed and according to processor performance. For example, an image may be captured every 0.5 seconds, 0.25 seconds, or 1 second.

It may be determined whether a captured image includes a face. That is, it may be determined whether face information can be detected from the image captured by the camera. Specifically, based on attribute information of pixels in the image, such as contrast, gray scale, etc., the image may be searched for some pixel regions matching a face feature, to determine whether the image includes a face image.

In examples of the present disclosure, a face in an image collected may be detected through a CenterFace network, to determine whether a face image is included.

The technical solution of examples of the present disclosure is more applicable to electronic equipment such as a smart speaker, a smart robot, etc. Image collection is performed using a camera installed on the electronic equipment, and it is determined whether the image includes a face.

In S12, when the image includes a face, it is determined whether the face in the image is a face with closed eyes.

In examples of the present disclosure, after determining a face image in an image input by the user, a feature point in the face has to be identified in order to identify the face image, and determine whether the operator has generated the set behavior. In examples of the present disclosure, a feature point in a face mainly includes a face feature point such as an eye, a nose tip, a mouth corner point, an eyebrow, a cheek, etc., and a contour point of eyes, a nose, lips, eyebrows, cheeks, etc. Of course, if the image includes an image such as an ear, etc., the ear of the face and contour points of the ear may be determined as feature points of the face.

If there is any face, the any face image may be cut out according to a face detection box acquired by face detection. On the basis of face detection, feature point positioning may be performed on a cut out face image using an existing face feature point positioning algorithm, such as a Practical Facial Landmark Detectorlink (PFLD) network, to locate key feature points of the face automatically.

In examples of the present disclosure, it is also possible to perform posture correction on the cut out face image. For example, the face image may be corrected using determined face feature point coordinates. Face posture correction may disclose whether the face in the face image is with closed eyes, greatly improving accuracy in closed-eye detection, thereby improving accuracy in face posture estimation.

For each corrected face, a rectangle passing through four feature points respectively at two corners (i.e., left and right corners) of an eye, a highest point of an upper eyelid of the eye, and a lowest point of a lower eyelid of the eye, is connected according to coordinates of the four feature points. A left eye image and a right eye image are cut out according to the rectangle. In examples of the present disclosure, closed-eye detection is performed respectively on the left eye image and the right eye image cut out through a closed-eye detection method of Real-Time Blink Estimation in Natural Environments (RT-BENE) in a natural environment. The result of the closed-eye detection is whether the eyes are closed. If the result of closed-eye detection is that the left eye and the right eye are closed at the same time, the face is considered to be a closed-eye face, and it is determined that the face does not gaze at the target to be operated, and no subsequent step is performed. It is continued to perform a subsequent processing step for another face image, i.e., an open-eye face image.

In examples of the present disclosure, ruling out a closed-eye face image can reduce a misjudgment of face detection of a user behavior, increasing accuracy in operating instruction generation, as well as avoiding unnecessary computation.

In examples of the present disclosure, a normalized eye image is acquired by normalizing an open-eye face using an eye image normalization method such as Eye Image Normalization. Then, lines of sight of the left eye and the right eye are estimated respectively using a three-dimensional line-of-sight estimation method such as a GazeNet estimation method. The normalized eye image is input. A result of line-of-sight estimation is output, including a line-of-sight direction angle (yaw and pitch) in a normalized space. The average of the left eye and the right eye may be taken as the line-of-sight direction of the face. Taking the average may reduce an error in line-of-sight estimation, and may simplify subsequent computation and reduce computation time.

In S13, when the face in the image is not with closed eyes, a line-of-sight direction angle of a target to which the face belongs, and a distance between the face and an image collecting unit, are computed.

In examples of the present disclosure, the image collecting unit may be a camera or other sensors configured to collect images, etc. The image collecting unit may be provided on a target to be operated, such as a smart speaker, and the image collecting unit is a fixed accessory on the target to be operated, such as the smart speaker, for collecting an image to automatically generate an associated operating instruction, such as smart control such as face recognition.

In examples of the present disclosure, the line-of-sight direction angle of the target to which the face belongs is computed as follows.

An eye image in the image may be input to a pre-trained line-of-sight estimation model, outputting line-of-sight direction angles of a left eye and a right eye in the eye image. An average of the line-of-sight direction angles of the left eye and the right eye may be taken as the line-of-sight direction angle of the face.

It should be noted that the above-described line-of-sight estimation model may be, but not limited to, a combination of Eye Image Normalization and three-dimensional line-of-sight estimation such as a GazeNet.

In examples of the present disclosure, when the face in the image is not with closed eyes, the distance between the face and the image collecting unit may be computed as follows. A size of a face image may be determined. The distance between the face of the target and the image collecting unit may be computed based on the size of the face image and a resolution of a display unit of the image collecting unit.

Specifically, the average line-of-sight direction angle is computed as follows.

$\quad\left\{ \begin{matrix} {{E_{yaw} = {\left( {l_{yaw} + r_{yaw}} \right)/2}},} \\ {E_{pitch} = {\left( {l_{pitch} + r_{pitch}} \right)/2}} \end{matrix} \right.$

l_(yaw), l_(pitch) are line-of-sight direction angles of the left eye. r_(yaw), r_(pitch) are line-of-sight direction angles of the right eye. E_(yaw), E_(pitch) are average line-of-sight direction angles of the eyes of the face (yaw and pitch), respectively.

A line-of-sight angle acquired by line-of-sight estimation may be converted into a space vector, preparing for subsequent computation of the intersection of the line of sight and the target to be operated. The specific conversion formula is as follows.

$\quad\left\{ \begin{matrix} {{G_{x} = {{\cos\left( E_{pitch} \right)} \times {\sin\left( E_{yaw} \right)}}},} \\ {{G_{y} = {\sin\left( E_{pitch} \right)}},} \\ {G_{z} = {{\cos\left( E_{pitch} \right)} \times {{\cos\left( E_{yaw} \right)}\ .}}} \end{matrix} \right.$

(G_(x), G_(y), G_(z)) represents unit direction vectors along axes x, y, and z in the normalized space, respectively. The yaw and the pitch represent line-of-sight direction angles (yaw and pitch) in the normalized space acquired by line-of-sight estimation, respectively.

The coordinates of the feature points of pupils of the left eye and the right eye acquired are denoted as (l_(x),l_(y)) and (r_(x),r_(y)), respectively. The coordinates of the midpoint of the line connecting the pupils of the left eye and the right eye are computed, specifically as follows.

$\quad\left\{ \begin{matrix} {{E_{x} = {\left( {l_{x} + r_{x}} \right)/2}},} \\ {E_{y} = {\left( {l_{y} + r_{y}} \right)/2}} \end{matrix} \right.$

(E_(x), E_(y)) denotes the coordinates of the midpoint of the line connecting the pupils of the left and right eyes, in units of pixels.

For a face image cut out based on a collected image, the width and height of a face are denoted by w and h, respectively, in units of pixels. The resolution of the screen of the target to be operated is known. The width and height of the resolution of the screen of the target to be operated are denoted by w0 and h0, respectively, in units of pixels. Then, the actual straight-line distance between the eyes and the target to be operated may be computed approximately using the width and height of the face and the resolution of the target to be operated according to an engineering experience formula, specifically as follows.

${dist} = {\frac{18840}{\max\left( {{w*\frac{1436}{1920}*\frac{1920}{\max\left( {w_{0},h_{0}} \right)}},{h*\frac{1080}{1440}*\frac{1920}{\max\left( {w_{0},h_{0}} \right)}}} \right)} - {{8.8}5}}$

dist denotes the actual straight-line distance between the eyes and the target to be operated, in units of cm. An actual test verifies that the error in the computation precision of the formula is less than 10 cm, meeting a requirement on the computation precision.

The dimension of the distance dist is converted into units of pixels, acquiring E_(d), with a computation formula as follows.

$E_{d} = {dist*\frac{w_{0}}{w_{a}}}$

E_(d) denotes the actual straight-line distance between the eyes and the target to be operated, in units of pixel. w_(a) is the actual width of the target to be operated, such as a smart speaker, in cm. w₀ is the lateral resolution of the screen of the target to be operated.

Locations of the pupils and the target to be operated with respect to each other may be acquired according to the above computation. In the normalized space, three-dimensional location coordinates of the camera of the target to be operated are the origin (0,0,0) three-dimensional location coordinates of the midpoint of the line connecting the eyes of the face are (E_(x), E_(y), E_(d)), and the unit direction vector in the line-of-sight direction is (G_(x), G_(y), G_(z)).

In S14, it is determined whether the target has a set behavior based on the line-of-sight direction angle and the distance.

In examples of the present disclosure, the set behavior includes whether the line-of-sight direction of the target to which the face belongs falls on the target to be operated. It may be determined whether the target has a set behavior based on the line-of-sight direction angle and the distance, as follows. A landing point of a line of sight of the target on a display unit of the image collecting unit may be computed according to the line-of-sight direction angle and the distance. It may be determined whether the target has the set behavior according to the landing point.

The landing point of the line of sight of the target on the display unit of the image collecting unit may be computed according to the line-of-sight direction angle and the distance as follows. A line-of-sight direction vector may be determined according to the line-of-sight direction angle. Three-dimensional location coordinates of a midpoint of a line connecting a left eye and a right eye of the face of the target may be determined based on the distance and three-dimensional location coordinates of the image collecting unit. The landing point may be computed according to the line-of-sight direction vector and the three-dimensional location coordinates of the midpoint of the line connecting the left eye and the right eye of the face of the target.

It may be determined whether the target has the set behavior according to the landing point as follows. It may be determined whether the landing point is located within the display unit. When the landing point is located within the display unit, it may be determined that the target has the set behavior. When the landing point is located beyond the display unit, it may be determined that the target does not have the set behavior.

In examples of the present disclosure, it is determined whether the line-of-sight direction of the target to which the face belongs falls on the target to be operated. Specifically, the landing point of the line of sight on the target to be operated is computed as follows.

$\quad\left\{ \begin{matrix} {g_{x} = {E_{x} - {\frac{E_{d}}{G_{z}}*G_{x}}}} \\ {g_{y} = {E_{y} - {\frac{E_{d}}{G_{z}}*G_{y}}}} \end{matrix} \right.$

g_(x) is the abscissa of the intersection point of the line of sight direction and the target to be operated, in units of pixels. g_(y) is the ordinate of the intersection point of the line of sight direction and the target to be operated, in units of pixels. It may be easily determined whether the target to which the face belongs is gazing at the target to be operated according to the coordinates (g_(x),g_(y)) of the intersection point of the line-of-sight direction and the screen plane. Taking as an example the target to be operated of a common smart speaker with a screen, the camera is generally located at the center of the upper edge of the speaker screen. Therefore, it is determined whether the target to which the face belongs is gazing at the target to be operated, with a formula as follows

$\quad\left\{ \begin{matrix} {{{- \frac{w_{0}}{2}} < g_{x} < \frac{w_{0}}{2}},} \\ {{- h_{0}} < g_{y} < 0} \end{matrix} \right.$

The w0, h0 are the horizontal resolution and the vertical resolution of the screen of the target to be operated, respectively. g_(x) is the abscissa of the intersection point of the line-of-sight direction and the screen plane, in units of pixels. g_(y) is the ordinate of the intersection point of the line-of-sight direction and the screen plane, in units of pixels.

If the coordinates (g_(x),g_(y)) of the intersecting point of the line-of-sight direction and the screen plane meets the above formula, it is determined that the target to which the face belongs is gazing at the target to be operated, denoted as s_(i)=1. Otherwise, the target to which the face belongs is not gazing at the target to be operated, that is, s_(i)=0. s_(i) is a determination result indicating whether the eyes in the ith image are gazing at the target to be operated. The determination result indicating whether the target to which each face belongs is gazing at the target to be operated may form a set S={s₁, s₂, . . , s_(n)}.

As an implementation, in examples of the present disclosure, when the image includes multiple faces, it may be determined that the target has the set behavior when a target to which at least one of the multiple faces belongs has the set behavior.

Determination results indicating whether the target to be operated is gazed at may be counted. There is at least a user who is gazing at the target to be operated if there is at least one face in all faces that is gazing at the target to be operated, i.e., there is at least one element greater than zero in the set S. Otherwise, it is considered that no user is gazing at the target to be operated.

In order to improve accuracy in determination in examples of the present disclosure, the determination condition may be modified as determining that a target (that is, an operator) to which the face belongs is gazing at the target to be operated and then generating a corresponding operating instruction when multiple consecutive elements greater than 0 exist in S. In this way, when the target to which the face belongs keeps gazing at the target to be operated, it may be determined that the target to which the face belongs is to operate the target to be operated, and a corresponding operating instruction may be generated.

An operating instruction may be generated if the target to which the face belongs (i.e., the operator) gazes at the target to be operated, adjusting the target to be operated to a first state. The first state may be an awake state or a power-on state. The first state may also be a state opposite to the current state. That is, when the target to be operated is currently in a sleep state and the operating instruction is a waking-up instruction, the state of the target to be operated may be adjusted to the awake state. When the target to be operated is currently in a power-off state and the operating instruction is a power-on instruction, the state of the target to be operated may be adjusted to the power-on state.

That is, in examples of the present disclosure, the operating instruction may be a waking-up instruction, a power-on instruction, etc. That is, an operating instruction is automatically generated corresponding to the current state of the target to be operated. For example, when the target to be operated is in the power-off state, if it is detected that the target to which the face belongs is gazing at the target to be operated, the power-on instruction is generated to turn on the target to be operated. When the target to be operated is in the sleep state, if it is detected that the target to which the face belongs is gazing at the target to be operated, a waking-up instruction is generated to wake up the target to be operated.

The technical solution of examples of the present disclosure is applicable to a scene in which a smart target to be operated, such as a voice robot, a smart speaker, etc., is smartly operated. Of course, the target to be operated may also be electronic equipment such as a mobile phone, a notebook, a tablet computer, a game machine, etc. After the user behavior recognition application of examples of the present disclosure is installed in the electronic equipment, an operating instruction may be generated corresponding to recognition of the user behavior, to operate the electronic equipment.

FIG. 2 is a schematic diagram of a structure of a device for behavior recognition based on line-of-sight estimation according to an example of the present disclosure. As shown in FIG. 2, a device for behavior recognition based on line-of-sight estimation according to an example of the present disclosure includes a unit as follow.

A collecting unit 20 is configured to collect an image.

A detecting unit 21 is configured to detect whether the image includes a face.

A first determining unit 22 is configured to determine, for an image including a face, whether the face in the image is a face with closed eyes.

A computing unit 23 is configured to compute, in response to the face in the image being not with closed eyes, a line-of-sight direction angle of a target to which the face belongs and a distance between the face and an image collecting unit.

A second determining unit 24 configured to determine whether the target has a set behavior based on the line-of-sight direction angle and the distance.

As an implementation, the computing unit 23 is further configured to determine a size of a face image; and compute the distance between the face of the target and the image collecting unit based on the size of the face image and a resolution of a display unit of the image collecting unit.

As an implementation, the second determining unit 24 is further configured to:

determine a landing point of a line of sight of the target on a display unit of the image collecting unit according to the line-of-sight direction angle and the distance; and

determine whether the target has the set behavior according to the landing point.

As an implementation, the second determining unit 24 is further configured to:

determine a line-of-sight direction vector according to the line-of-sight direction angle;

determine three-dimensional location coordinates of a midpoint of a line connecting a left eye and a right eye of the face of the target based on the distance and three-dimensional location coordinates of the image collecting unit; and

compute the landing point according to the line-of-sight direction vector and the three-dimensional location coordinates of the midpoint of the line connecting the left eye and the right eye of the face of the target.

As an implementation, the second determining unit 24 is further configured to:

determine whether the landing point is located within the display unit.

When the landing point is located within the display unit, it may be determined that the target has the set behavior. When the landing point is located beyond the display unit, it may be determined that the target does not have the set behavior.

As an implementation, the computing unit 23 is further configured to:

input an eye image in the image into a pre-trained line-of-sight estimation model, outputting line-of-sight direction angles of a left eye and a right eye in the eye image; and

take an average of the line-of-sight direction angles of the left eye and the right eye as the line-of-sight direction angle of the face.

As an implementation, the second determining unit 24 is further configured to:

in response to the image comprising multiple faces, determine that the target has the set behavior in response to a target to which at least one of the multiple faces belongs having the set behavior.

As an implementation, the first state includes at least one of:

an awake state, or a power-on state.

In an illustrative example, the collecting unit 20, the detecting unit 21, the first determining unit 22, the computing unit 23, the second determining unit 24, etc., may be implemented by one or more Central Processing Units (CPU), Graphics Processing Units (GPU), base processors (BP), Application Specific Integrated Circuits (ASIC), DSPs, Programmable Logic Devices (PLD), Complex Programmable Logic Devices (CPLD), Field-Programmable Gate Arrays (FPGA), general purpose processors, controllers, Micro Controller Units (MCU), Microprocessors, or other electronic components, or may be implemented in conjunction with one or more radio frequency (RF) antennas, for performing the foregoing device.

A module as well as unit of the device for behavior recognition based on line-of-sight estimation according to an aforementioned example herein may perform an operation in a mode elaborated in an aforementioned example of the method herein, which will not be repeated here.

FIG. 3 is a block diagram of electronic equipment 800 according to an illustrative example. As shown in FIG. 3, the electronic equipment 800 supports multi-screen output. The electronic equipment 800 may include one or more components as follows: a processing component 802, a memory 804, a power component 806, a multimedia component 808, an audio component 810, an Input/Output (I/O) interface 812, a sensor component 814, and a communication component 816.

The processing component 802 generally controls an overall operation of the display equipment, such as operations associated with display, a telephone call, data communication, a camera operation, a recording operation, etc. The processing component 802 may include one or more processors 820 to execute instructions so as to complete all or some steps of the method. In addition, the processing component 802 may include one or more modules to facilitate interaction between the processing component 802 and other components. For example, the processing component 802 may include a multimedia module to facilitate interaction between the multimedia component 808 and the processing component 802.

The memory 804 is configured to store various types of data to support operation on the electronic equipment 800. Examples of these data include instructions of any application or method configured to operate on the electronic equipment 800, contact data, phonebook data, messages, images, videos, and/or the like. The memory 804 may be realized by any type of volatile or non-volatile storage equipment or combination thereof, such as Static Random Access Memory (SRAM), Electrically Erasable Programmable Read-Only Memory (EEPROM), Erasable Programmable Read-Only Memory (EPROM), Programmable Read-Only Memory (PROM), Read-Only Memory (ROM), magnetic memory, flash memory, magnetic disk, or compact disk.

The power component 806 supplies electric power to various components of the electronic equipment 800. The power component 806 may include a power management system, one or more power supplies, and other components related to generating, managing and distributing electric power for the electronic equipment 800.

The multimedia component 808 includes a screen providing an output interface between the electronic equipment 800 and a user. The screen may include a Liquid Crystal Display (LCD) and a Touch Panel (TP). If the screen includes a TP, the screen may be realized as a touch screen to receive an input signal from a user. The TP includes one or more touch sensors for sensing touch, slide and gestures on the TP. The touch sensors not only may sense the boundary of a touch or slide move, but also detect the duration and pressure related to the touch or slide move. In some examples, the multimedia component 808 includes a front camera and/or a rear camera. When the electronic equipment 800 is in an operation mode such as a shooting mode or a video mode, the front camera and/or the rear camera may receive external multimedia data. Each of the front camera and/or the rear camera may be a fixed optical lens system or may have a focal length and be capable of optical zooming.

The audio component 810 is configured to output and/or input an audio signal. For example, the audio component 810 includes a microphone (MIC). When the electronic equipment 800 is in an operation mode such as a call mode, a recording mode, and a voice recognition mode, the MIC is configured to receive an external audio signal. The received audio signal may be further stored in the memory 804 or may be sent via the communication component 816. In some examples, the audio component 810 further includes a loudspeaker configured to output the audio signal.

The I/O interface 812 provides an interface between the processing component 802 and a peripheral interface module. The peripheral interface module may be a keypad, a click wheel, a button, etc. These buttons may include but are not limited to: a homepage button, a volume button, a start button, and a lock button.

The sensor component 814 includes one or more sensors for assessing various states of the electronic equipment 800. For example, the sensor component 814 may detect an on/off state of the electronic equipment 800 and relative locationing of components such as the display and the keypad of the electronic equipment 800. The sensor component 814 may further detect a change in the location of the electronic equipment 800 or of a component of the electronic equipment 800, whether there is contact between the electronic equipment 800 and a user, the orientation or acceleration/deceleration of the electronic equipment 800, and a change in the temperature of the electronic equipment 800. The sensor component 814 may include a proximity sensor configured to detect existence of a nearby object without physical contact. The sensor component 814 may further include an optical sensor such as a Complementary Metal-Oxide-Semiconductor (CMOS) or Charge-Coupled-Device (CCD) image sensor used in an imaging application. In some examples, the sensor component 814 may further include an acceleration sensor, a gyroscope sensor, a magnetic sensor, a pressure sensor, or a temperature sensor.

The communication component 816 is configured to facilitate wired or wireless/radio communication between the electronic equipment 800 and other equipment. The electronic equipment 800 may access a radio network based on a communication standard such as WiFi, 2G, 3G, . . . , or a combination thereof. In an illustrative example, the communication component 816 broadcasts related information or receives a broadcast signal from an external broadcast management system via a broadcast channel. In an illustrative example, the communication component 816 further includes a Near Field Communication (NFC) module for short-range communication. For example, the NFC module may be realized based on Radio Frequency Identification (RFID), Infrared Data Association (IrDA), Ultra-WideBand (UWB) technology, BlueTooth (BT) technology, and other technologies.

In an illustrative example, the electronic equipment 800 may be realized by one or more of Application Specific Integrated Circuits (ASIC), Digital Signal Processors (DSP), Digital Signal Processing Device (DSPD), Programmable Logic Devices (PLD), Field Programmable Gate Arrays (FPGA), controllers, microcontrollers, microprocessors or other electronic components, to implement the method.

In an illustrative example, a transitory or non-transitory computer-readable storage medium including instructions, such as the memory 804 including instructions, is further provided. The instructions may be executed by the processor 820 of the electronic equipment 800 to implement a step of the method for behavior recognition based on line-of-sight estimation of an example herein. For example, the computer-readable storage medium may be a Read-Only Memory (ROM), a Random Access Memory (RAM), a Compact Disc Read-Only Memory (CD-ROM), a magnetic tape, a floppy disk, optical data storage equipment, etc.

Examples of the present disclosure further disclose anon-transitory computer-readable storage medium having stored therein instructions which, when executed by a processor of electronic equipment, allow the electronic equipment to implement a control method. The method includes:

collecting an image;

detecting whether the image includes a face;

in response to the image including a face, determining whether the face in the image is a face with closed eyes;

in response to the face in the image being not with closed eyes, computing a line-of-sight direction angle of a target to which the face belongs and a distance between the face and an image collecting unit; and

determining whether the target has a set behavior based on the line-of-sight direction angle and the distance.

Optionally, computing the distance between the face and the image collecting unit includes:

determining a size of a face image; and

computing the distance between the face of the target and the image collecting unit based on the size of the face image and a resolution of a display unit of the image collecting unit.

Optionally, determining whether the target has the set behavior based on the line-of-sight direction angle and the distance includes:

determining a landing point of a line of sight of the target on a display unit of the image collecting unit according to the line-of-sight direction angle and the distance; and

determining whether the target has the set behavior according to the landing point.

Optionally, determining the landing point of the line of sight of the target on the display unit of the image collecting unit according to the line-of-sight direction angle and the distance includes:

determining a line-of-sight direction vector according to the line-of-sight direction angle;

determining three-dimensional location coordinates of a midpoint of a line connecting a left eye and a right eye of the face of the target based on the distance and three-dimensional location coordinates of the image collecting unit; and

computing the landing point according to the line-of-sight direction vector and the three-dimensional location coordinates of the midpoint of the line connecting the left eye and the right eye of the face of the target.

Optionally, determining whether the target has the set behavior according to the landing point comprises:

determining whether the landing point is located within the display unit;

in response to the landing point being located within the display unit, determining that the target has the set behavior; and

in response to the landing point being located beyond the display unit, determining that the target does not have the set behavior.

Optionally, computing the line-of-sight direction angle of the target to which the face belongs includes:

inputting an eye image in the image into a pre-trained line-of-sight estimation model, outputting line-of-sight direction angles of a left eye and a right eye in the eye image; and

taking an average of the line-of-sight direction angles of the left eye and the right eye as the line-of-sight direction angle of the face.

Optionally, the method further includes:

in response to the image including multiple faces, determining that the target has the set behavior in response to a target to which at least one of the multiple faces belongs having the set behavior.

Optionally, the first state includes at least one of:

an awake state, or a power-on state.

Further note that although in drawings herein operations are described in a specific order, it should not be construed as that the operations have to be performed in the specific order or sequence, or that any operation shown has to be performed in order to acquire an expected result. Under a specific circumstance, multitask and parallel processing may be advantageous.

Other implementations of the present disclosure will be apparent to a person having ordinary skill in the art that has deemed the specification and practiced the present disclosure. The present disclosure is intended to cover any variation, use, or adaptation of the present disclosure following the general principles of the present disclosure and including such departures from the present disclosure as come within common knowledge or customary practice in the art. The specification and the examples are intended to be illustrative only, with a true scope and spirit of the present disclosure being indicated by the appended claims.

It should be understood that the present disclosure is not limited to the exact construction that has been described above and illustrated in the accompanying drawings, and that various modifications and changes may be made to the present disclosure without departing from the scope of the present disclosure. It is intended that the scope of the present disclosure is limited only by the appended claims.

According to a first aspect of examples of the present disclosure, there is provided a method for behavior recognition based on line-of-sight estimation, including:

collecting an image;

detecting whether the image includes a face;

in response to the image including a face, determining whether the face in the image is a face with closed eyes;

in response to the face in the image being not with closed eyes, computing a line-of-sight direction angle of a target to which the face belongs and a distance between the face and an image collecting unit; and

determining whether the target has a set behavior based on the line-of-sight direction angle and the distance.

Optionally, computing the distance between the face and the image collecting unit includes:

determining a size of a face image; and

computing the distance between the face of the target and the image collecting unit based on the size of the face image and a resolution of a display unit of the image collecting unit.

Optionally, determining whether the target has the set behavior based on the line-of-sight direction angle and the distance includes:

determining a landing point of a line of sight of the target on a display unit of the image collecting unit according to the line-of-sight direction angle and the distance; and

determining whether the target has the set behavior according to the landing point.

Optionally, determining the landing point of the line of sight of the target on the display unit of the image collecting unit according to the line-of-sight direction angle and the distance includes:

determining a line-of-sight direction vector according to the line-of-sight direction angle;

determining three-dimensional location coordinates of a midpoint of a line connecting a left eye and a right eye of the face of the target based on the distance and three-dimensional location coordinates of the image collecting unit; and

computing the landing point according to the line-of-sight direction vector and the three-dimensional location coordinates of the midpoint of the line connecting the left eye and the right eye of the face of the target.

Optionally, determining whether the target has the set behavior according to the landing point includes:

determining whether the landing point is located within the display unit;

in response to the landing point being located within the display unit, determining that the target has the set behavior; and in response to the landing point being located beyond the display unit, determining that the target does not have the set behavior.

Optionally, computing the line-of-sight direction angle of the target to which the face belongs includes:

inputting an eye image in the image into a pre-trained line-of-sight estimation model, outputting line-of-sight direction angles of a left eye and a right eye in the eye image; and

taking an average of the line-of-sight direction angles of the left eye and the right eye as the line-of-sight direction angle of the face.

Optionally, the method further includes:

in response to the image including multiple faces, determining that the target has the set behavior in response to a target to which at least one of the multiple faces belongs having the set behavior.

According to a second aspect of examples of the present disclosure, there is provided a device for behavior recognition based on line-of-sight estimation, including:

a collecting unit configured to collect an image;

a detecting unit configured to detect whether the image includes a face;

a first determining unit configured to determine, in response to the image including a face, whether the face in the image is a face with closed eyes;

a computing unit configured to compute, in response to the face in the image being not with closed eyes, a line-of-sight direction angle of a target to which the face belongs and a distance between the face and an image collecting unit; and

a second determining unit configured to determine whether the target has a set behavior based on the line-of-sight direction angle and the distance.

Optionally, the computing unit is further configured to determine a size of a face image; and compute the distance between the face of the target and the image collecting unit based on the size of the face image and a resolution of a display unit of the image collecting unit.

Optionally, the second determining unit is further configured to:

determine a landing point of a line of sight of the target on a display unit of the image collecting unit according to the line-of-sight direction angle and the distance; and

determine whether the target has the set behavior according to the landing point.

Optionally, the second determining unit is further configured to:

determine a line-of-sight direction vector according to the line-of-sight direction angle;

determine three-dimensional location coordinates of a midpoint of a line connecting a left eye and a right eye of the face of the target based on the distance and three-dimensional location coordinates of the image collecting unit; and

compute the landing point according to the line-of-sight direction vector and the three-dimensional location coordinates of the midpoint of the line connecting the left eye and the right eye of the face of the target.

Optionally, the second determining unit is further configured to:

determine whether the landing point is located within the display unit;

in response to the landing point being located within the display unit, determine that the target has the set behavior; and in response to the landing point being located beyond the display unit, determine that the target does not have the set behavior.

Optionally, the computing unit is further configured to:

input an eye image in the image into a pre-trained line-of-sight estimation model, outputting line-of-sight direction angles of a left eye and a right eye in the eye image; and

take an average of the line-of-sight direction angles of the left eye and the right eye as the line-of-sight direction angle of the face.

Optionally, the second determining unit is further configured to:

in response to the image including multiple faces, determine that the target has the set behavior in response to a target to which at least one of the multiple faces belongs having the set behavior.

According to a third aspect of examples of the present disclosure, there is provided electronic equipment including a processor and a memory for storing processor executable instructions. The processor is configured to implement a step of the method for behavior recognition based on line-of-sight estimation by calling the executable instructions in the memory.

According to a fourth aspect of examples of the present disclosure, there is provided a non-transitory computer-readable storage medium having stored therein instructions which, when executed by a processor of electronic equipment, allow the electronic equipment to implement a step of the method for behavior recognition based on line-of-sight estimation.

A technical solution provided by examples of the present disclosure may include beneficial effects as follows.

In examples of the present disclosure, an image is collected. It is detected whether the image includes a face. When the image includes a face, it is determined whether the face in the image is a face with closed eyes. When the face in the image is not with closed eyes, a line-of-sight direction angle of a target to which the face belongs, and a distance between the face and an image collecting unit, are computed. It is determined whether the target has a set behavior based on the line-of-sight direction angle and the distance. The set behavior includes that the line of sight of the target to which the face belongs falls on the target to be operated. With examples of the present disclosure, a user behavior is detected accurately, with great control accuracy, ensuring reliability of human-computer interaction based on the user behavior. 

What is claimed is:
 1. A method for behavior recognition, comprising: collecting an image, by an image collecting unit; detecting whether the image comprises a face; in response to the image comprising a face, determining whether the face in the image is a face with closed eyes, wherein the face in the image is a face of a target; in response to determining that the face in the image is not with closed eyes, computing a line-of-sight direction angle of the target, and a distance between the face and the image collecting unit; and determining whether the target has a set behavior based on the line-of-sight direction angle and the distance.
 2. The method of claim 1, wherein computing the distance between the face and the image collecting unit comprises: determining a size of a face image; and computing the distance between the face of the target and the image collecting unit based on the size of the face image and a resolution of a display unit of the image collecting unit.
 3. The method of claim 1, wherein determining whether the target has the set behavior based on the line-of-sight direction angle and the distance comprises: determining a landing point of a line of sight of the target on a display unit of the image collecting unit according to the line-of-sight direction angle and the distance; and determining whether the target has the set behavior according to the landing point.
 4. The method of claim 3, wherein determining the landing point of the line of sight of the target on the display unit of the image collecting unit according to the line-of-sight direction angle and the distance comprises: determining a line-of-sight direction vector according to the line-of-sight direction angle; determining three-dimensional location coordinates of a midpoint of a line connecting a left eye and a right eye of the face of the target based on the distance and three-dimensional location coordinates of the image collecting unit; and computing the landing point according to the line-of-sight direction vector and the three-dimensional location coordinates of the midpoint of the line connecting the left eye and the right eye of the face of the target.
 5. The method of claim 3, wherein determining whether the target has the set behavior according to the landing point comprises: determining whether the landing point is located within the display unit; in response to the landing point being located within the display unit, determining that the target has the set behavior; and in response to the landing point being located beyond the display unit, determining that the target does not have the set behavior.
 6. The method of claim 1, wherein computing the line-of-sight direction angle of the target comprises: inputting an eye image in the image into a pre-trained line-of-sight estimation model, outputting line-of-sight direction angles of a left eye and a right eye in the eye image; and taking an average of the line-of-sight direction angles of the left eye and the right eye as the line-of-sight direction angle of the face.
 7. The method of claim 1, further comprising: in response to the image comprising multiple faces of multiple targets, determining that the target has the set behavior in response to at least one of the multiple targets having the set behavior.
 8. An electronic equipment, comprising: a processor and a memory for storing processor executable instructions, wherein the processor is configured, by calling the executable instructions in the memory, to implement: collecting an image, by an image collecting unit of the electronic equipment; detecting whether the image comprises a face; in response to the image comprising a face, determining whether the face in the image is a face with closed eyes, wherein the face in the image is a face of a target; in response to determining that the face in the image is not with closed eyes, computing a line-of-sight direction angle of the target, and a distance between the face and the image collecting unit; and determining whether the target has a set behavior based on the line-of-sight direction angle and the distance.
 9. The electronic equipment of claim 8, wherein the processor is configured to compute the distance between the face and the image collecting unit by: determining a size of a face image; and computing the distance between the face of the target and the image collecting unit based on the size of the face image and a resolution of a display unit of the image collecting unit.
 10. The electronic equipment of claim 8, wherein the processor is configured to determine whether the target has the set behavior based on the line-of-sight direction angle and the distance by: determining a landing point of a line of sight of the target on a display unit of the image collecting unit according to the line-of-sight direction angle and the distance; and determining whether the target has the set behavior according to the landing point.
 11. The electronic equipment of claim 10, wherein the processor is configured to determine the landing point of the line of sight of the target on the display unit of the image collecting unit according to the line-of-sight direction angle and the distance by: determining a line-of-sight direction vector according to the line-of-sight direction angle; determining three-dimensional location coordinates of a midpoint of a line connecting a left eye and a right eye of the face of the target based on the distance and three-dimensional location coordinates of the image collecting unit; and computing the landing point according to the line-of-sight direction vector and the three-dimensional location coordinates of the midpoint of the line connecting the left eye and the right eye of the face of the target.
 12. The electronic equipment of claim 10, wherein the processor is configured to determine whether the target has the set behavior according to the landing point by: determining whether the landing point is located within the display unit; in response to the landing point being located within the display unit, determining that the target has the set behavior; and in response to the landing point being located beyond the display unit, determining that the target does not have the set behavior.
 13. The electronic equipment of claim 8, wherein the processor is configured to compute the line-of-sight direction angle of the target by: inputting an eye image in the image into a pre-trained line-of-sight estimation model, outputting line-of-sight direction angles of a left eye and a right eye in the eye image; and taking an average of the line-of-sight direction angles of the left eye and the right eye as the line-of-sight direction angle of the face.
 14. The electronic equipment of claim 8, wherein the processor is further configured to implement: in response to the image comprising multiple faces of multiple targets, determining that the target has the set behavior in response to at least one of the multiple targets having the set behavior.
 15. A non-transitory computer-readable storage medium having stored therein instructions which, when executed by a processor of electronic equipment, allow the electronic equipment to implement: collecting an image, by an image collecting unit; detecting whether the image comprises a face; in response to the image comprising a face, determining whether the face in the image is a face with closed eyes, wherein the face in the image is a face of a target; in response to determining that the face in the image is not with closed eyes, computing a line-of-sight direction angle of the target, and a distance between the face and the image collecting unit; and determining whether the target has a set behavior based on the line-of-sight direction angle and the distance.
 16. The storage medium of claim 15, wherein computing the distance between the face and the image collecting unit comprises: determining a size of a face image; and computing the distance between the face of the target and the image collecting unit based on the size of the face image and a resolution of a display unit of the image collecting unit.
 17. The storage medium of claim 15, wherein determining whether the target has the set behavior based on the line-of-sight direction angle and the distance comprises: determining a landing point of a line of sight of the target on a display unit of the image collecting unit according to the line-of-sight direction angle and the distance; and determining whether the target has the set behavior according to the landing point.
 18. The storage medium of claim 17, wherein determining the landing point of the line of sight of the target on the display unit of the image collecting unit according to the line-of-sight direction angle and the distance comprises: determining a line-of-sight direction vector according to the line-of-sight direction angle; determining three-dimensional location coordinates of a midpoint of a line connecting a left eye and a right eye of the face of the target based on the distance and three-dimensional location coordinates of the image collecting unit; and computing the landing point according to the line-of-sight direction vector and the three-dimensional location coordinates of the midpoint of the line connecting the left eye and the right eye of the face of the target.
 19. The storage medium of claim 17, wherein determining whether the target has the set behavior according to the landing point comprises: determining whether the landing point is located within the display unit; in response to the landing point being located within the display unit, determining that the target has the set behavior; and in response to the landing point being located beyond the display unit, determining that the target does not have the set behavior.
 20. The storage medium of claim 15, wherein computing the line-of-sight direction angle of the target comprises: inputting an eye image in the image into a pre-trained line-of-sight estimation model, outputting line-of-sight direction angles of a left eye and a right eye in the eye image; and taking an average of the line-of-sight direction angles of the left eye and the right eye as the line-of-sight direction angle of the face. 